New Study: Higher CO2 Levels Promote Leaf Growth

A new study entitled “Greening of the Earth and Its Drivers,” published online in the journal Nature Climate Change on April 25, shows an increase in “greening” (greater leaf area) over 25 to 50 percent of the Earth’s vegetated area, with CO2 fertilization explaining 70 percent of the observed greening trend.

The study was conducted by a team of 32 authors from 24 institutions in eight countries and was reported by BBC News after its lead author, Professor Ranga Myneni from Boston University, spoke with the British news organ.

BBC News noted in its report about “Greening of the Earth and Its Drivers”:

It is based on data from the Modis and AVHRR instruments which have been carried on American satellites over the past 33 years. The sensors show significant greening of something between 25% and 50% of the Earth’s vegetated land, which in turn is slowing the pace of climate change as the plants are drawing CO2 from the atmosphere.

“The greening reported in this study has the ability to fundamentally change the cycling of water and carbon in the climate system,” BBC News quoted another lead author of the study — Dr. Zaichun Zhu, from Peking University, Beijing, China — as saying.

Though the study seems to validate the point made by those who have touted the benefits of increased CO2 in the Earth’s atmosphere, including so-called global warming skeptics, its authors have not necessarily embraced that viewpoint. BBC reported that Myneni still maintains that “the extra tree growth would not compensate for global warming, rising sea levels, melting glaciers, ocean acidification, the loss of Arctic sea ice, and the prediction of more severe tropical storms.”

Another study co-author, Dr. Philippe Ciais, from the Laboratory of Climate and Environmental Sciences in Gif-sur-Yvette, France (who is also an Intergovernmental Panel on Climate Change [IPCC] author) also minimized the study’s obvious implications that rising CO2 levels are beneficial, telling BBC: “The fallacy of the contrarian argument is two-fold. First, the many negative aspects of climate change are not acknowledged. Second, studies have shown that plants acclimatize to rising CO2 concentration and the fertilization effect diminishes over time.”

However, the news article did quote an opposing opinion from Nic Lewis — an independent scientist who is often critical of the IPCC — who told BBC News:

The magnitude of the increase in vegetation appears to be considerably larger than suggested by previous studies.

This suggests that projected atmospheric CO2 levels in IPCC scenarios are significantly too high, which implies that global temperature rises projected by IPCC models are also too high, even if the climate is as sensitive to CO2 increases as the models imply.

The Intergovernmental Panel on Climate Change (IPCC) is a UN agency set up by two UN organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP). As was noted in an article in The New American on April 8:

BBC News also quoted Professor Judith Curry, the former chair of earth and atmospheric sciences at the Georgia Institute of Technology, who said:

It is inappropriate to dismiss the arguments of the so-called contrarians, since their disagreement with the consensus reflects conflicts of values and a preference for the empirical (i.e. what has been observed) versus the hypothetical (i.e. what is projected from climate models).

These disagreements are at the heart of the public debate on climate change, and these issues should be debated, not dismissed.

Curry was one of several environmental scientists profiled in an article posted by The New American last January, entitled: “Meet the Climate Realists.” That article noted:

[Curry’s] research in 2005 on the intensity of tropical storms and hurricanes related to global warming earned her a “prominent place among climate scientists,” relates Van Jensen in the Georgia Tech Alumni Magazine. But when the 2009 “Climategate” e-mail scandal hit, revealing correspondence between UN researchers that suggested fraudulent reporting of data to favor their political agenda, Curry says she “saw it as a threat to the IPCC and all of climate science, largely because of this trust issue.”…

“Curry lost her place in the IPCC clique,” wrote Jensen. Suddenly, “her opinions were called ‘unconstructive,’ full of ‘factual misstatements,’ and ‘completely at odds’ with her previous position on global warming.” Yet Curry maintains her belief in the warming effect of human-generated carbon dioxide. What keeps her blacklisted is that she disputes the obsessive focus on one atmospheric gas as the main driver of climate variability. While she told Jensen that her goal is “to bring together the polarized sides of climate debate and return scientists’ focus to thorough research,” it’s likely the IPCC will continue ignoring her as a disloyal provocateur.

The New American has published numerous article about the climate change/global-warming debate, and many of these have cited the views of scientists who believe that higher levels of CO2 are beneficial — not the source of countless gloom-and-doom scenarios such as the melting of the polar ice caps and rising seas levels that threaten to flood the world’s coastal areas. One such article last January reported statements provided by scientist Robert Carter, former chief of the School of Earth Sciences at Australia's internationally renowned James Cook University, made during the Heartland Institute’s “Day of Examining the Data” conference held in Paris last December.

In an interview with The New American after his presentation, Carter made a statement that supported the findings of the newly released “Greening of the Earth and Its Drivers” study: The CO2 added to the atmosphere in recent decades has been responsible for a tremendous greening of the planet. “That’s a huge environmental benefit,” he said, adding that much of the greening had occurred along arid areas such as the Sahara Desert.

“If you talk to most scientists, they will acknowledge that carbon dioxide is not a pollutant,” explained Dr. Carter. “Indeed, it’s grotesque to call it a pollutant. It’s an abuse of logic, it’s an abuse of language, and it's an abuse of science.... Carbon dioxide is literally the stuff of life.”

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